Sox will monitor Doubront's transition to 'pen

Without the need for a fifth starter, Farrell said Doubront will be available out of the bullpen next weekend for the final two games of the regular season, but Doubront suggested that he had not been told of any such plans.

Even if Doubront gets a chance out of the 'pen before the season is over, Farrell is concerned that the lefty won't have enough time to transition to a relief role before the postseason begins.

"I know he's made some comments lately on the adjustments to his routine and what that might mean," Farrell said. "The difficult thing will be, when he's first available next weekend, how many opportunities can he get a look at from there."

Doubront had a breakout season as a starter in 2013, but he began to break down late in the year and required 2 1/2 weeks of rest between starts. Farrell said he was concerned with Doubront's stamina.

While the Red Sox have placed Ryan Dempster in the bullpen for the rest of the season, the adjustment may not be quite as seamless for Doubront, who has far less experience in that role.

"Obviously we've got some decisions to make when it comes to the postseason roster," Farrell said. "And all things will be taken into account."

Jason Mastrodonato is a reporter for MLB.com. Follow him on Twitter @jmastrodonato. This story was not subject to the approval of Major League Baseball or its clubs.